Conveyor for dishwasher



Jan. 14, 1964 c. R. WElHE, JR.. ETAL 3,117,558

CONVEYOR FOR DISHWASHER Filed Jan., 22, 1962 3 Sheets-Sheet l A Fz g' .1. B l I I a U 3 it 1rI G. Gm'oio,

Jan. 14, 1964 c, w JR" ETAL 3,117,668

CONVEYOR FOR DISHWASHER 3 Sheets-Sheet 2 Filed Jan. 22,

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Jan. 14, 1964 c. R. WEIHE, JR.. ETAL 3,117,663

CONVEYOR FOR DISHWASHER 3 Sheets-Sheet 3 Filed Jan. 22, 1962 Izwenfiwfls: Ciyde R. WeaL'oze,Ja Edzvaa d 6. 63 0330 United States Patent Ofifice Elllfih Patented Jan. 14, 1954 3,117,658 CONVEYOR FOR DISHWASHER Clyde R. Weihe, In, Needham, and Edward C. Grotto, Newton, Mass, assignors to Adams Manufacturing Co., Inc., Waltharn, Mass., a corporation of Massachusetts Filed Jan. 22, 1962, tier. No. 167,542 Claims. (Cl. 198-181) This invention relates to commercial dishwashing systems of the type employing a conveyor to move racks of dishes through a washing machine, and pertains more particularly to improvements in the conveyor construction. The present application is a continuation-in-part of our application Serial No. 805,225, filed April 9, 1959, now abandoned.

A commercial dishwashing system of the type to which this invention pertains consists essentially of an endless track having a portion passing through a washing machine having sets of nozzles for spraying the dishes with wash water and rinse water, a train of dollies carrying racks for receiving dishes, and means for driving the dolly train around the track.

The principal objects of this invention are to provide a track which is easy to clean and to provide a dolly train which may be readily dismantled and assembled, which runs easily, and which is adaptable to many types of installations.

Other objects and advantages will be apparent from the following description.

In the drawings illustrating the invention:

FIG. 1 is a plan view of a conveyor table with a set of linked dollies, constructed according to the invention;

FIG. 2 is an enlarged fragmentary cross-section of the table taken along line 2--2 of FIG. 1;

FIG. 3 is an enlarged fragmentary cross-section taken along line 33 of FIG. 1;

FIG. 4 is an enlarged fragmentary cross-section taken along line 44 of FIG. 1 showing one of the dollies in the process of assembly on to the track;

FIG. 4a is a fragmentary plan view of the table in the region of the notch shown in FIG. 4;

FIG. 5 is an enlarged plan view, partly broken away, of a series of dollies, illustrating the manner of connecting them together;

FIG. 6 is an enlarged fragmentary cross-section taken along line 66 of FIG. 5; and

FIG. 7 is a side elevation of the conveyor table, the slope of the table being shown somewhat exaggerated for clarity.

The conveyor table, generally indicated by the numeral 10 is preferably made or corrosion-resistant material such as stainless steel, and fabricated from formed or rolled sections welded together to provide smooth continuous surfaces throughout. The conveyor is oval shaped in plan but may be made in other shapes to fit particular installations, providing that any bends are of sufiiciently large radius to permit the dollies to negotiate them without difiiculty. The conveyor at one point passes through a continuous type of dishwashing machine schematically indicated by the dotted outline 11 where the washing and rinsing operations take place. The conveyor is supported by any suitable means, such as legs (not shown) at a convenient height for the kitchen personnel to load and unload dishes.

The table as seen in transverse section has a fiat bottom 12, a pair of side walls 13 extending obliquely upward and inward from the bottom 12, a pair of side walls 14 extending obliquely inward from the upper edges of walls 13, and a pair of rims 15 extending outward from the upper edges of walls 14.

The dollies, generally indicated by the numeral 20, are all of similar construction, consisting of a rectangular frame 21, preferably made of stainless steel angles, mounted by means of angle brackets 22 on cross bars 2-3. A pair of braces 24 is connected between cross-bars 23.

Mounted on the ends of bars 23, which project beyond the brackets, are four roller assemblies. Each assembly, as exemplified in FIG. 6, consists of a shaft 25 secured by means of a bolt 26, and a roller 27, preferably mounted on ball bearings (not shown) on the shaft. The rollers are frusto-conical in shape, with their large diameter rims 27a disposed at the bottom. These rims are somewhat rounded.

The pairs of walls 13 and 14 together form V-shaped tracks, in which rollers 27 ride along both sides of the table. These walls are continuous around the entire table. As shown in FIGS. 4 and 4a, a dimple or notch 28 is formed in one of the tracks at one point on the table, by

pressing out a portion of the wall 14 and an adjacent portion of the rim 15. If the notch is disposed in the inner track, for example, a dolly may be placed on the table by inserting the outer rollers 27 sidewise into the outer track, pushing one of the inner rollers down through notch 28, rolling the dolly along until the other inner roller is in register with the notch and then pushing it down. Similarly a dolly may be removed by lifting the inner rollers one at a time out through the notch, and then drawing the outer rollers sidewise out of the outer track. The table is made wide enough so that rollers 27 engage walls 13 slightly below their junction with walls 14, leaving enough clearance between the rollers and the deepest portion of the track to permit the dollies to be tilted slightly to allow their removal and insertion. The table is also widened slightly in the curved portions to permit the dollies to pass around smoothly.

In the region of the dishwashing machine, for example, between the exit end A and entrance end B in FIG. 1, the rims 15 are cut away, and the bottom of the table has an opening 30. The drive mechanism for the series of dollies is disposed in this region and consists of a chain 31, driven in a conventional manner by suitable sprockets and motor (not shown). The chain passes over a guide plate 32. Each dolly carries a dog 33 pivoted on a bracket 34. When a dolly enters the region of opening 3%, its dog drops down and engages chain 31 so that the dolly is driven by the chain. When the dolly again reaches the solid part of the table, its dog 33 swings back and rides along the bottom 12. The length of the driving portion of the chain is somewhat greater than the spacing between the dogs on successive dollies, so that the dog of at least one dolly will always be engaged with the chain.

The dollies are all linked together, as shown in FIGS. 5 and 6. The inner brace 24 carries at either end pins 35, 35a with rounded top. A link 36, consisting of a straight bar with holes 37 in each end, rotatably engages pin 35. One link 36 has its rear end engaged with pin 35 on the forward end of the inner brace 24 of the dolly shown in full in FIG. 5, and a similar link 36 has its forward end engaged with pin 35a. The dollies all carry similar pins and each of the links shown has its opposite end engaged with a pin on an adjacent dolly. A leaf spring 38 mounted on bar 23 has a free end overlying pin 35 and a similar spring 38a overlies pin 35a. The springs prevent the ends of the links from riding oil the pins when the conveyor is in operation, but may be raised to connect or disconnect a link.

Some, or all of the dollies, carry a rubber wiper 40 which sweeps along the bottom 12 of the table to remove food which falls off the soiled dishes when they are loaded. In the particular assembly illustrated in FIG. 1, the dishwashing machine has a pre-rinse station I, a wash station H, and a final rinse station III. A waste disposal unit or waste receptacle may be disposed under the table. The conveyor drive mechanism, previously described,

drives the linked dollies in the direction of arrow 41, or

counter-clockwise around the table. The table is sloped slightly downward from point A, or the end of the final rinse station, counter-clockwise around to point B, or the beginning of the pre-rinse station. Any Water draining from the dishes as they emerge from the final rinse, runs around the table to the pre-rinse station and assists the cleaning action of wiper 40.

It is understood that dish racks of any suitable type are set on the dollies. The conveyor moves slowly enough so that soiled dishes may be placed in the racks and clean dishes removed at convenient locations on the table, Without interrupting the conveyor operation.

While the washing machine and conveyor are in operation, the continuous wiping action of the wipers on the dollies tends to keep the table clean. Occasionally, however, it may be desirable to clean the table more thoroughly. To do this, the train of dollies may be dismantled by lifting oif the links, and taking the dollies off one by one by lifting their inner rollers up through notch 28 as previously described. When all the dollies have been removed, the table may be hosed down or otherwise Washed. Because of the slope of the table, the wash water will run ofi at the pre-rinse station in the machine. After cleaning, the dolly train may be readily replaced on the table. No tools are required for dismantling or re assembling the train. 'If a dolly becomes damaged it can be readily replaced in a few minutes.

The linkage construction permits mass production of dollies of a single size for use on various table installations. The length of the train may be adjusted to tables of different lengths by using more or fewer dollies and links of diiferent lengths. The track or table is likewise made up of straight and curved pre-formed sections of sheet metal which may be produced in quantity and Welded together in various arrangements to produce tracks of various shapes and sizes.

' The one-piece construction of the table and tracks makes the table easy to clean. The conical shape of the rollers provides a small bearing surface so that friction is reduced to a minimum. The smooth oblique track permits the rollers to ride up or down and compensate for variations in width so that precise alignment of the track and rollers is not required for smooth operation of the conveyor system. The rigid links maintain the desired 4 spacing between the dollies, so that they, and the dishes thereon, will not strike each other going around the corners or pile up in the event that the conveyor becomes jammed.

The washing apparatus may consist of a sequence of washing and rinsing nozzles all mounted in a single cabinet, or a series of separate washing and rinsing devices through which the dishes pass in succession; The term machine, as used herein refers generally to both types of installations, entrance end refers to the point at which the dishes enter the first stage of the washing process and exit end to the point where the dishes emerge from the final stage.

What is claimed is:

1. A conveyor, for a dishwashing system of the type having a washing machine with an entrance end and an exit end, comprising a track having a first portion passing through said machine and a second portion extending outside said machine from said exit end to said entrance end, said second portion having a closed bottom, a first pair of side walls extending obliquely outwardly therefrom, and a second pair of side walls, one overhanging each of said first side walls, and a train of dish carriers mounted on said track and having rollers engaged with said first pair of side walls under said second pair.

2. A conveyor as described in claim 1, said rollers being frusto-conical in shape and having lower outer rims providing their sole engagement with said track.

3. A conveyor as described in claim 1, said track having a notch in one of said second pair of side walls, said notch being of a size to permit one of said rollers to be lifted out and dropped in therethrough.

4. A'conveyor as described in claim 1, said bottom being substantially flat from one of'said first side walls.

to the other and sloping continuously downward from said exit end to said entrance end.

5. A conveyor as. described in claim 1, said second track portion having rims flaring outwardly from said second pair of side walls.

References Cited in the file of this patent UNITED STATES PATENTS 1,973,005 Lemmon Sept. 11, 1934 2,109,899 Cannon Mar. 1, 1938 2,591,009 Riche Apr. 1, 1 952 

1. A CONVEYOR, FOR A DISHWASHING SYSTEM OF THE TYPE HAVING A WASHING MACHINE WITH AN ENTRANCE END AND AN EXIT END, COMPRISING A TRACK HAVING A FIRST PORTION PASSING THROUGH SAID MACHINE AND A SECOND PORTION EXTENDING OUTSIDE SAID MACHINE FROM SAID EXIT END TO SAID ENTRANCE END, SAID SECOND PORTION HAVING A CLOSED BOTTOM, A FIRST PAIR OF SIDE WALLS EXTENDING OBLIQUELY OUTWARDLY THEREFROM, AND A SECOND PAIR OF SIDE WALLS, ONE OVERHANGING EACH OF SAID FIRST SIDE WALLS, AND A TRAIN OF DISH CARRIERS MOUNTED ON SAID TRACK AND HAVING ROLLERS ENGAGED WITH SAID FIRST PAIR OF SIDE WALLS UNDER SAID SECOND PAIR. 